Thermostat



A. J. OTTO THERMOSTAT July 8 1924.-

2 Sheets-Sheet. l

Filed June 18 Patented July 8, 1924.

UNI/TED STATES ARTHUR J. OTTO, OF 'MILWAUKEE WISCONSIN, ASSIGNOR TOJOHNSON SERVICE COM- PAT-ENT OFFICE.

PANY, OF MILWAUKEE, WISCONSLNQA CORPORATION 'AOF WISCONSIN.

THERMOSTAT.

Application filed June 18,

To all whom t may concern:

Be it known that I, ARTHUR J. O'r'ro, a citizen of the United States,residing at Mil- Waukee, in the county of Milwaukee and v State ofWisconsin, have invented certain new and useful Improvements' inThermostats, of which the following is a speoification.

The present invention relates to automatic control of atmosphericconditions such as temperature, humidity and the like, and resides incertain structural improve` ments in automatic control devices of th,pressure operated relay type. The chief object ofthe invention is toproduce a compact device of simple and inexpensive construction, capableof precise and certain operation and constructedof metal throughout soas to avoid packed joints and leather and fabric diaphragms heretoforecommonly used in this art.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in'which--- A Fig. 1 is a front elevation ofthedevice with parts broken away to show the internal construction ;r

Fig. 2 is a vertical sectional viewf differ-i ent portions of the devicebeing sectioned on different planes soas to, illustrate various of theports and chambers; y

Fig. 3 is a section on the line 8 3 of Fig: 1; y

ig. 4 is a sectionvontheV line 4-4 of 85 Fi 1.

the drawings the usual cover or casing is omitted as it forms no partdof the invention. Y The body 6 of the instrument consists of a castingformed with certain portsxand chambers hereinafter described in detail.The general form is subject to some variation, but that illustrated inthe drawing is` pr`e ferred because it is compact` and because the 4.5ports canl be easily formed by drilling.

The front of the body 6 is rovided with.

a cover 7 which is held inv lace by screws in the usual manner. Thejoint between the cover 7 andthe body 6 is sealed by means of aninterposed gasket 8 and this gasket is provided with apertures which.register with the communicating ports inthe body 6 and cover 7. Thecover 7 closes the front 1923. serial No. saloni. A,

face of the relay motor chamber 9 formed inthe body 6.

The` body 6 is formed with a seat 10 dev Vsigned to fit and seal againsta pipe head tting familiar to those skilled in the art, and

notshown in the drawings. This fitting is this construction the body 6is properly connected to theelipes by merely mounting i' it on the pipeh To effect this result, the seat 10 is formed with a supply recess 11from which the supply ports lead. One of these, the main motor supplyport, is indicated at 12 and leads to the main inlet valve chamber 13.The main inlet valve 14 is mounted in this chamber and seats in thedirection of flow to the relay motor chamber 9.v The valve 144 is guidedby a combined valve guide and spring seat 15 which isthreaded into thevalve chamber 13 from the rear of the body 6, and which is provided witha vsealing Hang? so as tomake a fluid tight 'oint with the ody. A spring16 confine between the member 15 and the valve 14 urges the velve in a'eieeed direction. u will be 0bserved that a-portion of the valveprojects into the relay motor chamber 9 far enough l to be engaged by aplate or lever actuator hereinafter described. e

from the supply recess 11 is' Also leading a relay supp y port 17 whichdischarges past a restricting needle valve 18 into a continuing port 2Oalsov formed in the body 6.

The needle valve 18 is threaded into an vented by 'alse'aling plug l19inthe usual v manner.

vaperture inthebody 6 andleakage is pre-'fil i The port 20in the body 6leads through f anpaperture in the gasket 8 to 'a'port 21 formed in thecoverl 7.

the cover a branch 22 which leads to the diaphragm chamber 23. Thisdiaphragm chamber is enclosed by a flexible front wall 24 and a flexiblerear wall 25 composed of light sheet metal` formed with annular vcorrugations. The frontwall and rear'wall-are 'connected This portextends 1 across the covervand, has at the center of controlled by atransparent' Celluloid valve 29 which is carried by a responsive element30 in the usual manner and which is so moved by'the response of theelement 30 to changes in atmospheric condition as to seat against theend of the leak tube or move morefor less far from the same, thusproducing a variable throttling effect on the outflow through the leakport.

-In the use of the device the needle valve 18 is so adjusted' that the-flow past it is less than the capacity of the port in the leak tube 28.From this it results that the variable throttlingof the leak p ort bythe valve 29 produces a variable pressure in the diaphragm chamber 23. i

' The responsive element 3() is illustrated as consisting of abi-metallic thermostatic bar. Any other responsive element such, forexample, as a hygrostatic element mightHi be substituted and suchsubstitution would commonly involve minor changes in the,l mounting ofthe element such as to enable it to produce the desired movement of thevalve member 29.

In the example illustrated, the responsive element 30 is mounted on asaddle 31 which, 1s supported by horizontal pivot screwrsr 32 i, 6.hisl` carried by brackets on the bod j saddle is urged to rotate A on tese pivot screws bythe springs 33 so as to seat against the end of anauxililary adjusting. Screw 3 4 which serves to x its position. Thescrew 34 is threaded through a main adjustmg screw 35 which carries anarcuate dial against which reads a combined index and detent spring 37.`The auxiliary adjusting screw 34 provides an initial adjustment by whichthe instrument is zeroed when installed. The user adjusts the res onse.of the instrument from time to time Iby turning the dial 36 and conseuently the screw 35. Adjustments so made are indicated on the dial-bythe index 37 (see 'Fig'. 1).

Communicating with the rear of the'relay motor chamber 9 is an exhaustvalve chamber 38 formed with an exhaust valve seat' 39. The exhaustvalve 40 seats outward against the seat 39 and is guided by the exhaustvalve guide 41 threaded into the'inner end of the chamber 38 andprovided with ports Aforl the passage of air.- The exhaust valve 491surged open by the exhaust valve spring 42 and is provided with a portionwhich extends through the guide 41 and projects into the relay motorchamber 9.

The exhaust valve spring 42 is weaker than the inlet'valve spring 16 andthe two valves are actuated through a triangular actuator plate 43 bythe movements of the diaphragm member. This plate 43 is suscentral bossl45 by the diaphragm and is supported in opposition to this stress atthree points, namely: on the pin 44, the valve 14 and the valve 40.

Since the spring 16 is stronger than hthe spring 42 pressure exerted bythe diaphragm on the plate 43 will lirst close the'exhaust valve 40 andthen open the'inlet valve 14. On reverse movement the inlet valve willclose before the exhaust valve ispermitted to open, therefore, thedevice will operate to establish a pressure in the diaphragm motorchamber 9 which follows the pressure created Within the diaphragmchamber 23 through the varying throttling action of valve 29 as it ismoved by the responsive element 30.

The pressure so created in the chamber I9 is transmitted to thecontrolled motor by the motor control port 46 vwhich leads from `thechamber 9 vto a recess 47 in the seat 10. As is understood, the recess47 communicates with a` pipe connection in the pipe head heretoforedescribed7 such connection leading to l 'plate v43 produces a sim leconstruction which gives the desired serlal action of the inlet andexhaust valves.

-' It will be observed that all ports are ac` cessible for inspectionand repair and that their construction is such as to permit inexpensivemanufacture.-

v What is claimed is:

1. In anl automatic control device, the

on through said lever mechanism, and to exert a predominant resistanceon oneof said valves, vvhereby said valves are caused to open, one at atime by the lever mechanism in different positlons thereof and bothvalves are closed in 'an intermediate position; a diaphragm subject onone side to the pressure controlled b said valves, and arranged toactuate said lever mechanism; a responsive element arranged to control aiuid pressure acting against the `other side of said diaphra and meansfor subjecting a controlle device to the first named pressure. v v

2. In an automatic control device, the combination of independentlymovable inlet and exhaust valves, a lever mechanism constructed andarranged to balance an openingstress exerted thereby on one of saidvalves against a closing stress simultaneously exerted thereby on theother of said valves;

resilient means arranged to resist movements of the valves under thestresses exerted thereon through said lever mechanism, and to exert apredominant resistance on one of said valves, whereby said valves arecaused to open, one at a time, by the lever mechanism in differentpositions thereof and both valves are closed in an intermediateposition;

a metallic diaphragm motor arranged to actuate said lever mechanism andurged in one direction by the pressure controlled by said valves; aresponsive element arranged to control a luld pressure urging saiddiaphragm motor in the opposite direction; and means for subjecting acontrolled device to the first named pressure.

3. A control device com rising fixed structural parts providing a uidpressure supply passa eand a dehvery passage connected y a supp y port,and having an exhaust port connectin said delivery passage toatmosphere; va ves controlling said supply port and said exhaust port;unequal springs, the dominant spring urging said supply valve closed andthe other spring urging said ex- `haust valve open; a bearing plateloosely engaging said valves and serving when moved 1n one direction tourge said valves simul-V taneously in op osition to their springs; anexpansible mem er positioned to engage said plate and ymove it in thedirection aforesaid; means for supplying and exhausting pressure iluidto operate said expansible member;

andan element responsive to changes in the medium to be controlledserving to control said supplyingand exhausting means.

In testimony whereof I have signed my name 'to this specification.

ARTHUR J. OTTO.

